Engineering Specification

Transcription

1 Engineering Specification Electrical 33KV AC INDOOR SWITCHGEAR NON-WITHDRAWABLE Owner: Approved by: Chief Engineer, Electrical Neal Hook Chief Engineer Electrical Authorised by: Version 2.1 Issued May 2013 Neal Hook Chief Engineer Electrical Disclaimer This document was prepared for use on the RailCorp Network only. RailCorp makes no warranties, express or implied, that compliance with the contents of this document shall be sufficient to ensure safe systems or work or operation. It is the document user s sole responsibility to ensure that the copy of the document it is viewing is the current version of the document as in use by RailCorp. RailCorp accepts no liability whatsoever in relation to the use of this document by any party, and RailCorp excludes any liability which arises in any manner by the use of this document. Copyright The information in this document is protected by Copyright and no part of this document may be reproduced, altered, stored or transmitted by any person without the prior consent of RailCorp. Engineering Specification UNCONTROLLED WHEN PRINTED Page 1 of 31

2 Document control Version Date Summary of change July 2004 Last Technical Review 2.0 May 2010 Application of TMA 400 format. 2.1 May 2013 Update template RailCorp Page 2 of 31

3 Contents 1 Scope and Application General Application Reference Standards International Standards Australian Standards RailCorp Standards Key RailCorp Standards: Other RailCorp Standards: Definitions, Terms and Abbreviated Terms Definitions and Terms Abbreviated terms: Background Functional Characteristics Performance Characteristics General Switchboard Ratings Technical Characteristics General Standard Switchboard Configurations Rated Insulation Level Control Voltage DC auxiliary supply voltage Busbar Gas insulation (where applicable) Earthing bar HV Cable interface Surge arresters Current Transformers Voltage Transformers General Directional Protection Supply Alarm Voltage Transformer Alarm Circuit-breakers General Circuit Breaker Type Vacuum Circuit-Breakers SF 6 Circuit-breakers Circuit-breaker operating mechanisms Circuit-breaker Operation and Control Circuit-breaker operation coils Indication Interlocks Circuit Earthing Facilities...18 RailCorp Page 3 of 31

4 7.16 Padlocking Auxiliary Equipment Instruments, Transducers and Metering General Transducers Ammeters Voltmeters Watthour meter Busbar and Circuit Protection General Feeder Protection System Transformer Protection Rectifier Controls and Protection SCADA Indications and Controls Binary Indications Analogue Indication Controls Circuit Test Facilities Integrated System Support Requirements Integrated Support Objectives Equipment Supplier Deliverable Tests Routine Tests Type Tests Data Set associated with the Equipment Information Technical Schedule (Appendix A) Life Cycle Costing...24 Appendix A Technical Schedule...25 Appendix B RFT Checklist...30 Appendix C Requirements for Technical Aspects of Tender Evaluation...31 RailCorp Page 4 of 31

5 1 Scope and Application 1.1 General This document specifies the characteristics of factory assembled, non-withdrawable switchgear designed for indoor installation on RailCorp sub-transmission systems operating at nominal 33kV a.c., three-phase, 50 Hz. The requirement is for Switchboards of three, four and five SCADA controlled circuit breaker panels suitable for deployment in linear or ring bus configurations. Where a busbar is to be divided into two or more sections each section will comprise a separate Switchboard Unit, physically separated from the other unit(s) and connected by a tie cable through a tie circuit breaker at each end of the tie cable. Only circuit breakers are included. Specific circuit breaker panel configuration requirements are set out for the following applications: feeder, bus (switchboard) tie, rectifier transformer, system transformer. The switchgear panels will in general each include equipment that comprises a fixed circuit-breaker, with an associated off-load disconnector and earthing facility, in combination with the associated control, measuring, indicating, alarm, and protective equipment, including interconnections, accessories, enclosures and supporting structure. The protection and control equipment is located in or immediately above the relevant circuit breaker panel. Details of the required protection schemes are specified in RailCorp standard EP SP Protection System Requirements for the High Voltage Network. The switchboard shall incorporate the applicable requirements of EP SP. Specific details for the rectifier transformer circuit breaker protection and control are to be in accordance with EP SP Controls & Protection for Rectification Equipment. Busbar voltage transformers are required for all switchboard units. In the event of major failure it is anticipated that the entire switchboard unit would be replaced rather than attempting on-site replacement of a single panel. The switchgear is intended for indoor use under ambient conditions as specified in RailCorp standard EP SP. 1.2 Application The requirements of this document apply when a new 33kV indoor switchboard is installed in a RailCorp substation. The requirements of this document are not applicable to existing 33kV indoor switchboards currently in service in the RailCorp network. RailCorp Page 5 of 31

6 2 Reference Standards The following documents contain provisions that, through reference in this text, constitute provisions of this specification. 2.1 International Standards IEC 61958, 2000 IEC 62063, 1999 IEC , 2003 IEC , 2001 IEC , 2003 IEC , 1997 IEC , 1984 IEC , 1984 IEC , 1984 High-voltage prefabricated switchgear and control gear assemblies - Voltage presence indicating systems High-voltage switchgear and control gear - The use of electronic and associated technologies in auxiliary equipment of switchgear and control gear High-voltage switchgear and control gear - Part 100: Highvoltage alternating-current circuit-breakers High-voltage switchgear and control gear - Part 102: Alternating current disconnectors and earthing switches High-voltage switchgear and control gear - Part 200: A.C. metal-enclosed switchgear and control gear for rated voltages above 1 kv and up to and including 52 kv Direct acting indicating analogue electrical measuring instruments and their accessories Part 1: Definitions and general requirement common to all parts Direct acting indicating analogue electrical measuring instruments and their accessories Part 2: Special requirements for ammeters and voltmeters Direct acting indicating analogue electrical measuring instruments and their accessories Part 3: Special requirements for wattmeters and varmeters Direct acting indicating analogue electrical measuring instruments and their accessories Part 7: Special requirements for multifunction instruments 2.2 Australian Standards AS Bushings for Alternating Voltages above 1000V. AS High Voltage A.C. Switchgear and controlgear Disconnectors(Isolators) and earthing Switches AS International Electrotechnical Vocabulary. Chapter 441: Switchgear, control gear and fuses AS Degrees of Protection Provided by Enclosures for Electrical Equipment (IP Code). AS Switchgear assemblies and ancillary equipment for alternating voltages above 1 kv AS Common specifications for high-voltage switchgear and control gear standards AS Colour Standards for General Purposes. AS Instrument transformers - Current Transformers. AS Instrument transformers - Voltage transformers AS High-voltage switches - Switches for rated voltages above 1 kv and less than 52 kv AS In service Safety inspection & testing of electrical equipment. RailCorp Page 6 of 31

7 2.3 RailCorp Standards Key RailCorp Standards: Several significant sets of requirements applicable to 33kV AC Indoor Switchgear (non withdrawable) are common to other classes of equipment and are set out in the following RailCorp standards. The equipment shall comply with the relevant requirements set out therein. EP SP EP SP EP SP EP SP Electrical Power Equipment - Integrated Support Requirements Common Requirements for Electric Power Equipment Controls & Protection for Rectification Equipment Protection System Requirements for the High Voltage Network Other RailCorp Standards: EP SP EP SP EP SP Electrical Power Equipment - Design Ranges of Ambient Conditions Insulation Coordination and Surge Arrester Selection Standard Voltage Tolerances 3 Definitions, Terms and Abbreviated Terms 3.1 Definitions and Terms For the purpose of this specification, the terms, definitions and abbreviated terms in AS and the following apply: Circuit-breaker a mechanical switching device that is capable of making, carrying and breaking currents under normal circuit conditions, and also of making, carrying for a specified time and breaking currents under specified abnormal conditions, such as those of a short-circuit. Circuit-breaker panel a switchgear panel complete with a fixed circuit-breaker, switchdisconnector, earthing switch and protection & control equipment. Earthing switch as defined in (AS 1852(441) ). Fixed circuit-breaker a circuit-breaker which is not a withdrawable part of the panel assembly it which it is mounted. Metal-clad switchgear metal-enclosed switchgear in which certain components, for example, circuit-breakers, are arranged in separate compartments that have metal partitions and that are intended to be earthed. Non-withdrawable switchgear switchgear that contains circuit-breaker and switches, which are not a withdrawable part of the panel assembly in which they are mounted. Rated insulation level the combination of the rated lightning impulse withstand voltage and the rated short duration power frequency withstand voltage specified in AS Rated normal current for main circuits and switching devices, the r.m.s. value of the current that they are designed to carry continuously under the specified conditions of use and behaviour. RailCorp Page 7 of 31

8 Rated peak withstand current for main and earthing circuits, the peak current associated with the first major loop of the short-time withstand current that a mechanical switching device is designed to carry in the closed position under prescribed conditions of use and behaviour. Rated short-time withstand current for main and earthing circuits, the r.m.s. value of current that the switching device is designed to carry in the closed position during a specified short time under prescribed conditions of use and behaviour. Rated voltage the highest r.m.s. phase-to-phase voltage of the supply on which the switchgear is designed to operate. Switch a mechanical switching device that is capable of making, carrying and breaking currents under normal circuit conditions, which can include specified operating overload conditions, and also capable of carrying for a specified time, currents under specified abnormal circuit conditions such as those of a short-circuit. Switchboard two or more switchgear panels coupled together in various combinations. Switch-disconnector as defined in AS 1852(441) Switchgear a general term that covers switching devices and their combination with associated control, measuring, indicating, alarm, protective and regulating equipment, also assemblies of such devices and equipment with associated interconnections, accessories, enclosures and supporting structures, intended, in principle, for use in connection with the generation, transmission, distribution and conversion of electric energy. Switchgear panel (or panel) switchgear of modular design that comprises a mechanical switching device, for example, a circuit breaker, a switch-disconnector, a switch-fuse combination or a switch. Withdrawable as defined in AS 1852(441) Abbreviated terms: CT Current Transformer VT Voltage Transformer 4 Background RailCorp operates a high voltage AC network in which the nominal voltages used are 11kV, 33kV, 66kV and 132kV. RailCorp also operates a 1500V DC network that supplies power for electric traction. The majority of RailCorp substations are traction substations where transformers and rectifiers convert the high voltage AC supply (33kV or 66kV) to 1500V DC. The majority of the existing 33kV traction substations have outdoor 33kV switchyards comprising circuit breakers, air-break switches, instrument transformers and busbars along with the rectifier transformers and system transformers. Protection and control equipment is located inside the associated substation building. Other 33kV traction substations have an indoor 33kV switchboard(s), which comprise of the 33kV busbar, 33kV circuit-breakers, cable boxes and protection and control equipment. An indoor 33kV switchboard is the preferred method for the protection and control of the 33kV network. RailCorp Page 8 of 31

9 5 Functional Characteristics The 33kV indoor switchgear covered by this standard shall: Provide a 33kV busbar and busbar voltage transformer. Provide for connection of 33kV feeders, bus tie cables, rectifier and power transformer circuits to the 33kV busbar. Provide for isolation and earthing of feeders, bus tie cables, rectifier and power transformer circuits. Provide protection and control for 33kV feeders, rectifier and power transformer circuits and sections on the 33kV busbar. Provide the means to perform a DC cable test on the HV cables, without disturbing existing HV cable connections. Note: There is no requirement to provide a facility to earth the busbar. 6 Performance Characteristics 6.1 General The switchboard shall be designed and manufactured in accordance with following standards: AS 2067, AS 2650 and IEC , Except where specifically varied in this standard. It shall have the following characteristics: Number of Phases 3 Nominal System Voltage 33kV non effectively earthed Type Installed Metal Clad Indoors Insulation Air, cast resin, or SF 6 Circuit-breakers Busbar Non withdrawable Single Table 1 - Switchgear characteristics The switchboard shall be suitable for the environmental conditions as described in RailCorp standard: EP SP, Electrical Power Equipment - Design Ranges of Ambient Conditions. Similar components of all equipment shall be capable of being interchanged. RailCorp Page 9 of 31

10 6.2 Switchboard Ratings The switchgear shall have the following general ratings: Rating Type Rated voltage Line to Earth Voltage Rating Rated frequency Rated Normal Current - Busbar Rated Normal Current Feeder and Bus Tie Circuit Breaker Panels (steps as per R10 series defined in IEC 60059) Rated Normal Current Rectifier Transformer Circuit Breaker Panels Rating 36 kv Suitable for Resistively Earthed System 50Hz 1250 amps (min) 630 A, 800 A, or 1250 A 630 A Rated Insulation Level: Minimum Rated peak lightning impulse withstand voltage Rated short-duration power-frequency withstand r.m.s. voltage Rated short-time withstand current I k Rated peak withstand current I p Rated duration of short-time current t k Rated Short Circuit Breaking Current Rated Short Circuit Making Current Rated Operating Sequence Internal Arc Classification (As per IEC , Annex A; Defined 3.132) 170kV 70kV 31.5kA 80kA 3 second desired (1 sec minimum) 31.5kA 80kA O - 0.3s-CO-3min-CO AFLR Internal arc 25 ka, 1 s Table 2 - Switchgear Ratings RailCorp Page 10 of 31

11 7 Technical Characteristics 7.1 General Switchgear shall comply with the requirements of IEC , AS Specifically, the Switchgear shall meet all Internal Arc Classification (IAC) criteria as proven by test in accordance with Annex A of IEC Standard Switchboard Configurations While a large number of combinations of panels are possible, to simplify logistic support a number of preferred standard configurations have been identified. The switchgear panels shall be assembled into switchboard units of three, four or five circuit-breaker panels. Each switchboard unit shall include a bus bar voltage transformer (VT). The three, four or five circuit-breaker panel switchboards shall be referred to according to the particular circuit-breaker function combination. Standard circuit breaker functions are: Feeders, Rectifiers, System Transformers and Bus-ties. The functional requirements of each standard circuit breaker are described in the specification EP SP, Protection System Requirements for the High Voltage Network. The naming conventions for standard switchboard combinations is in accordance with the table below: Standard Switchboard Configuration Table Circuit Breaker Function Configuration Type Feeders Rectifiers System Transformers Bus Ties Table 3 - Switchboard configuration type Figure 1 is an example of a 310 and a 420 switchboard combined in a linear bus via a separate cable. These boards would be physically separated to reduce likelihood of consequential damage to the a neighbouring switchboard in the event of a major switchboard failure. RailCorp Page 11 of 31

12 Figure 1 - Example Switchboard configuration Switchboards with single bus tie panels should have the bus tie at one end of the switchboard. Switchboards with two bus tie panels should have the bus tie panels at opposite ends of the switchboard. Otherwise order is not important. 7.3 Rated Insulation Level All switchgear of like manufacture shall have the same Rated Peak Lightning Impulse Withstand Voltage. 7.4 Control Voltage DC auxiliary supply voltage The auxiliary supply voltage shall be 120 V d.c.(nominal). Auxiliary supply voltage requirements are specified in EP SP, Common Requirements for Electric Power Equipment. 7.5 Busbar All joints and tees in busbars and busbar connections shall be made with an approved connection type. If bolts, nuts and washers are used they shall be suitably protected against corrosion in accordance with ISO Putty and tape shall not be used. 7.6 Gas insulation (where applicable) Sulfur-hexafluoride (SF 6 ) insulated switchgear shall be filled with SF 6 that complies with the requirements of IEC The switchgear shall be factory sealed so as to not require any routine gas replenishment during installation or in normal service. The design, construction and sealing of gas compartments shall be such that the gas will not require replenishment for 20 years. RailCorp Page 12 of 31

13 It is preferred that switchgear that that requires gassing after panels are assembled in to switchboards be gassed at the factory and transported to site as a single unit. Only if specifically approved by RailCorp, shall gas compartments be assembled, gassed and sealed on site. In this situation the supplier shall test the tightness, in accordance with AS 2650 Section 6.1, and shall certify and warrant for gas tightness. A device for monitoring the SF 6 pressure in each gas compartment while in service shall be provided. This device shall provide indication of the minimum permissible pressure level for safe operation and shall provide two level alarms - level 1 alarm, level 2 alarm and operation inhibit. The pressure level monitoring device shall be clearly visible to the operator from the operating side of the switchgear panel. 7.7 Earthing bar To assist with stray current mitigation measures from the dc traction system, it may be necessary to connect 33kV cable screens to a separate cable screen earth bar. This arrangement is to facilitate future installation of a transient earth clamp. The transient clamp acts as a DC decoupler, to provide DC isolation between earthing points that are still AC connected. Under an AC earth fault the clamp impedance momentarily changes state to a virtual short circuit, acting to provide a direct connection of HV cable screens to the switchboard earth bar. The transient earth clamp provides a blocking path to dc stray current that could otherwise use the cable screen as a path. Note some HV panels will require all HV earth screens to be directly connected to the switchboard earth bar. Each switchgear panel shall include two copper earthing bars, rated for maximum fault levels and not less than 120 mm 2 cross section area to facilitate earthing. The cable screen earth bar shall be connected to the switchboard earth bar via removable links and shall be isolated from similar bars in adjacent panels. It shall be insulated from the frame of the switchboard by insulated mounts that have been rated for maximum earth potential rise and tested for at least 15kV for 1 minute. The cable screen earth bar shall provide for connection of the two removable links, four HV cable screens and mounting holes for a transient earth clamp. The switchboard earth bar shall interconnect adjacent switchgear panels and provide:- for all switchgear bonding for two cable connections to the main substation earth grid for two removable links per panel for connection to the insulated earth screen earthing bar (per panel) for connection of four HV cable screens mounting holes for a transient earth clamp To provide for mounting of the transient earth clamp the two earth bars, ie the switchboard earth bar and the cable screen earth bar, shall be vertically separated as far as possible to provide sufficient space for future insertion of the transient earth clamps. Earth termination requirements are provided in EP SP, Common Requirements for Electric Power Equipment. RailCorp Page 13 of 31

14 7.8 HV Cable interface Each circuit-breaker panel shall be equipped with a HV cable compartment providing a dead-break, separable, insulated and shielded system for connection of HV cables. The separable insulated shielded connection system is to be compliant with AS 2629 and relevant ratings specified in Table 2, at Section 6.2. At least two single core XLPE insulated 33kV cables per phase of up to 630mm 2 cross section rated for 1250 Amp shall be accommodated. The cables shall enter the cable compartment from below. The minimum of two cables shall be achieved without sacrificing space for surge arrester equipment. Details of cable connection and restrictions shall be nominated in schedule A. The cable termination shall be capable of withstanding the power frequency test as specified in Table 1 of AS Each circuit breaker panel is to provide the means to perform a DC cable test on the HV cables, without disturbing existing HV cable connections. See Section Surge arresters The switchgear may be installed with short cable feeds. Sufficient space shall be provided within the cable compartment of each feeder cubicle to install surge diverters if required for the specific feeding configuration. Surge arrester type and restrictions shall be nominated in Appendix A Current Transformers The circuit-breaker panels shall be provided with three phase sets of protection current transformers and three phase sets of metering current transformers in compliance with EP SP, Protection System Requirements for the High Voltage Network Voltage Transformers General A three-phase, voltage transformer in compliance with EP SP, Protection System Requirements for the High Voltage Network shall be provided for each switchboard. For maintenance, and for the commissioning of protection relays, it shall be possible to simulate the voltage conditions that would occur during earth faults and the supplier shall explain how this is achieved (see Appendix A, item 49). A typical way to achieve this is to remove the high-voltage fuse in any one phase and earth that phase of the voltage transformer. RailCorp Page 14 of 31

15 Directional Protection Supply Alarm Within each panel the low voltage side of the voltage transformer supply shall be protected by a separate circuit-breaker of adequate breaking capacity complete with voltage free contacts. The main voltage transformer secondary circuit-breaker should discriminate for faults protected by the individual panel circuit-breakers. For each section of the busbar the normally closed auxiliary contacts shall be wired in series to provide a single directional protection alarm in accordance with EP SP, Protection System Requirements for the High Voltage Network, Section 4.6 Protection alarms Voltage Transformer Alarm A three phase, phase failure relay in compliance with EP SP, Protection System Requirements for the High Voltage Network shall be connected to the secondary of the voltage transformer Circuit-breakers General Circuit-breaker panels shall comprise of a fixed circuit-breaker, switch-disconnector and earthing switch. Circuit-breakers shall comply with the requirements of AS 2650 and IEC Circuit-breakers, switch-disconnector and earthing switches that have long mechanical and electrical endurance (as defined in IEC parts 100 & 102) are preferred. The protection and control equipment shall be located in or immediately above the relevant circuit breaker panel. Details of the required protection schemes are specified in RailCorp standard EP SP Protection System requirements for the high voltage network. The switchboard shall incorporate the applicable requirements of EP SP. Specific details for the rectifier transformer circuit breaker protection and control are to be in accordance with EP SP Controls & Protection for Rectification Equipment Circuit Breaker Type The interrupting medium shall be either vacuum or SF Vacuum Circuit-Breakers Means shall be provided for testing the units for loss of vacuum without the necessity of removal of the units. The contacts of the interrupter shall be held open by a positive fail-safe device independent of interrupter vacuum. The closing arrangement shall be designed so as to give a positive closing action whilst overcoming the contact hold open device. RailCorp Page 15 of 31

16 SF 6 Circuit-breakers Each circuit-breaker shall consist of three separate "pole units" mounted on a single piece frame and shall be mechanically interconnected. The design of the interrupting mechanism and contacts shall be such that the energy dissipated in the SF 6 gas is low and does not cause appreciable degradation of gas. Each pole shall be provided with a separate and independent set of main and arcing contacts to minimise degradation of main contacts during fault interruption. The arcing contacts shall be terminated by tungsten or similar tips and shall be of a high electrical endurance. The main contacts shall be capable of carrying the maximum short circuit current without damage. If butt type arcing contacts are provided, it shall be possible to check the wear of arcing contacts without the necessity to open pole units. The internal surfaces of all porcelains shall not be glazed. The circuit-breakers shall be guaranteed to have a leakage rate of less than 1% mass per year of the quantity of SF6 used for filling. Means shall be provided to check the internal pressure of the pole units. The gas tightness shall be obtained by elimination of any part likely to wear or age. Certificates and details of tests for tightness carried out on pole units of breakers shall be maintained Circuit-breaker operating mechanisms The circuit-breaker operating mechanism shall be an integral part of the circuit breaker. Any part of the circuit breaker mechanism that requires routine inspection and maintenance shall not be enclosed in any gas tight compartment. Solenoid based mechanisms are subject to RailCorp approval. A full failure mode and reliability analysis is required for approval. All circuit-breakers in the closed position shall be able to trip-close-trip before the spring needs to be charged again. All circuit circuit-breaker panels shall be the XEM type (stored energy operation by means of energy stored in a motor-charged spring with manual or electrical release) Circuit-breaker Operation and Control The circuit-breaker closing mechanism shall be electrically operated, trip-free. The circuit-breaker mechanism shall provide lockout preventing closing, as specified in Section of AS 1852 (441): Feeder, Bus Tie and System Transformer circuit breakers shall be arranged for operation by local control or by remote supervisory control. The supervisory equipment will provide an open or close command signal of 1.0 A maximum at the nominated DC control voltage for up to 1.0 second. The control arrangements for rectifiers shall be in accordance with EP SP, Controls & Protection for Rectification Equipment. The circuit-breaker shall close without delay when the close command signal is applied. While this command signal is applied, the circuit-breaker shall not make a second attempt to close if it fails to close on the first attempt. The circuit-breaker shall open without delay when the open command signal is applied independently to any of the trip coils or to all trip coils simultaneously. RailCorp Page 16 of 31

17 A mechanical push-button or similar device for tripping the circuit-breaker shall be provided. Continuously rated control equipment to make the successful closing of the circuitbreaker independent of the length of time that the control switch is held in the CLOSE position and to ensure that only one closing attempt can be made if the control switch is held in the CLOSE position Circuit-breaker operation coils The circuit-breaker shall have one close coil and two trip coils. All operating coils of the control contactors associated with the solenoid-operated closing device shall be rated for continuous operation Indication The circuit-breaker panel shall have indication clearly visible from the front of the panel (i.e. either on the circuit-breaker or on the circuit-breaker panel). The circuit-breaker switchgear panel shall have the following definite indication: a) circuit-breaker open/close; b) switch disconnector open/close (if applicable); c) earth switch position; d) stored energy device charged/discharged; e) non-resetable mechanical operation counter Interlocks Facilities provided for operational access to parts of the switchgear panel that contain live components shall be mechanically interlocked so that access to such parts is not possible unless all live parts have been rendered safe, either by a visibly applied earth connection or by being positively disconnected and screened from the remaining live parts. Mechanical interlocks shall be provided to ensure positive and substantial protection against malfunction, and shall be so designed and constructed as to ensure dependable fail-safe operation. Interlocks shall ensure that the disconnector cannot be moved unless the circuit-breaker is open. Interlocks shall ensure that the circuit breaker cannot be closed unless the disconnector is fully in the closed, isolated or earth position. Positive mechanical interlocking shall be provided to prevent inadvertent switching from the ON position to the EARTH position without a definite stop in the OFF position, or from the EARTH position to the ON position without a definite stop in the OFF position. Access to the test terminals shall only be possible when the associated earth switch is in the EARTH position. When the circuit test facility is in use, it shall not be possible to close the disconnector. RailCorp Page 17 of 31

18 It is preferred that the making of the disconnector contacts in the earth position shall be directly observable by the operator. If the earthing of a circuit-breaker panel is not visible from the operating position, the corresponding indication shall be directly coupled to the earthing mechanism, to ensure fail-safe indication. If the switchgear panel is designed so that the circuit to be earthed is earthed through the main contacts of the circuit breaker, then the circuit breaker must be interlocked so that it cannot be tripped by the protection relays or SCADA control while the circuit is earthed. An analysis shall be provided detailing the integrity of the interlocking system. The analysis shall include all possible failure modes and the controls employed to prevent an unsafe operation. A table shall be produced of all possible and inhibited states the switchgear may occupy Circuit Earthing Facilities Each panel shall be equipped with circuit earthing switches manufactured and tested in accordance with IEC Earth switches shall be the integral type. The earthing system shall be designed and tested for making a live circuit with a prospective peak fault current of 80 ka. Each circuit earthing switch shall be mechanically interlocked with the corresponding circuit-breaker in accordance with Section 7.14 of this specification. The earthing switch shall be rated for fault making if: the circuit to be earthed, is earthed through the main contacts of the circuitbreaker, AND if there is any identified failure mode which could result in the earth switch being closed onto a live circuit. Each switch shall be provided with a failsafe indicating device to positively indicate whether it is in the OPEN OR EARTH position and the words "OPEN" and "EARTH" shall be used for the respective indication of these positions. If the equipment is configured to allow the position of disconnector contact in the earth position to be directly observable, then appropriate illumination shall be provided. The preferred light source is white light emitting diodes. It shall be possible to replace the light source without the need for isolating any HV equipment or significant disassembly of the switchgear Padlocking Facilities shall be provided to padlock. f) the circuit-breaker in the open positions and the closed position while the disconnector is in the earthed position, and g) the disconnector in the closed, open and earth positions. h) the circuit test facility if applicable (see Section 7.14 and ) All padlocking facilities shall be suitable for padlocks with a 6mm shank diameter. RailCorp Page 18 of 31

19 7.17 Auxiliary Equipment Each switchgear panel, with the exception of the rectifier panel, shall be fitted with: a) A control panel with : i) A local CLOSE and OPEN switch or push-buttons coloured red and green respectively. ii) iii) LOCAL - SUPERVISORY changeover switch; Capability for installation of instrumentation to measure: Voltage Current Energy The requirement for which instruments are to be installed shall be specified at the time of order. The requirements of any instrumentation to be fitted, are set out in section 7.18 Instruments, Transducers and Metering- Instruments, transducers and metering iv) Live line indicators shall be provided for each of the three phases on each circuit and the busbar. Live line indicators shall comply with the requirements of IEC b) Two normally open and two normally closed auxiliary switches rated at 5 amperes in a 120 V d.c. inductive circuit or a 415 V a.c. circuit. (These auxiliary switches shall be provided in addition to those essential to the circuit-breaker operation or provided for already specified functions). c) A mechanically operated indicator, indelibly marked, to show whether the circuit-breaker is open or closed. The word OPEN shall be visible only if the circuit-breaker is open and the word CLOSED shall be visible only if the circuitbreaker is closed. If colours are used in addition, then the colour green shall indicate the open condition and the colour red shall indicate the closed condition. d) Electrically operated indicating lights of the LED type. e) A non-resettable operation counter. f) A set of terminals for the termination of auxiliary wiring. All auxiliary wiring such as for remote closing and tripping circuits, incoming DC control supplies and all spare auxiliary switches shall be connected to these terminals. g) Mechanical interlocks shall be provided in compliance with Section 5.11 of IEC to prevent unsafe operation, including: i) Automatic opening of a circuit-breaker when it is used to earth a circuit or the bus bar ii) Closing of an earthing switch unless the circuit-breaker is in the open position Each switchboard shall be fitted with a voltmeter to indicate the bus voltage. RailCorp Page 19 of 31

20 7.18 Instruments, Transducers and Metering General All instruments, transducers and metering equipment that are required to be fitted shall comply with this section and the relevant requirements in EP SP, Common Requirements for Electric Power Equipment. All indicating instruments shall be flush-mounted industrial type instruments that comply with the requirements of the relevant of IEC standards: IEC , IEC , IEC , IEC , IEC and IEC The instruments shall be clearly visible and easily readable from a standing position in front of the panel Scales shall have a scale length of at least 90 mm. All instruments on a switchboard shall be scaled with the same type of characters of the same size. All current-operated instruments shall be protected against continuous over current up to 120% of nominal value and high current surges up to the fault rating of the circuitbreaker Transducers Current measurements made for SCADA shall use the protection CTs to generate the measurements. Only one current measurement transducer per phase may be interposed between the CT and the protection relay. The approved transducers to be used to measure current are of the 0 20mA type and are specified in RailCorp standard: EP SP, Protection System Requirements for the High Voltage Network. The output of the current transducer shall be used to also drive the ammeter unless the transducer cannot drive both the ammeter and the SCADA measurement circuits. If the ammeter would impose excessive burden on the transducer then separate CTs must be used for metering. It is preferred that a suitable ammeter should be selected to avoid the need for additional metering CTs Ammeters Ammeters shall have analogue indication with scales that are essentially linear with the scale selected for the instrument accuracy class. Ammeter scales shall allow for 120% of the primary current rating of the current transformer. The current transformer ratio shall be clearly marked on the face of the ammeter. The accuracy of ammeters shall be 3 % or better and shall be stated in the Technical Schedule Voltmeters Voltmeter shall have analogue indication with scales that have an indicating range of 80 % to 120 % of the nominal system voltages. Where voltmeters that have a nominal range from 0 % to 120 % are required, this will be specified at time of order. The nominal voltage shall be marked in red on the scale. RailCorp Page 20 of 31

21 Watthour meter kwh meters shall be three phase, with pulse output. The pulse output rate shall be10 per kwh. Where required for revenue metering the kwh meter is to be connected to a metering CT of suitable rating and accuracy class Busbar and Circuit Protection General Protection schemes shall be in accordance with RailCorp specification EP SP, Protection System Requirements for the High Voltage Network Feeder Protection Primary feeder protection shall be feeder pilot wire. The feeder protection scheme on incoming feeders shall provide a means of implementing inter-tripping with circuit breakers at the supply end of the feeder where placement of protection CTs leaves a blind spot on the feeder side of the circuit breaker. The inter-trip scheme shall be implemented in accordance with specification EP SP, Protection System Requirements for the High Voltage Network. If implemented via dedicated inter-trip, then one set of voltage free normally open and normally closed contacts rated to switch 1Amp at 120V dc shall be provided where the feeder can be an incoming feeder. Circuit breakers for feeders that can be arranged as outgoing shall be configured to accept an intertrip signal System Transformer Protection The full set of protection functions required for system transformers including control of the circuit breaker on the other voltage side of the transformer shall be implemented within the 33kV panel Rectifier Controls and Protection The full set of control and protection functions required for rectifiers as set out in RailCorp standard EP SP - Rectifier Controls and Protection, including control of the DCCB shall be implemented within the 33kV panel. RailCorp Page 21 of 31

22 7.20 SCADA Indications and Controls Binary Indications The following status indications shall be provided to SCADA: I/O Point Description. Hard Wired Serial Link Circuit Breaker Opened & Closed. Circuit Breaker Faulted. Trip Circuit OK (trip supply OK). Gas/vacuum supervision Ok Isolator Position (Open, Closed) Earthing switch Position Protection Relay Faulted Protection relay watch dog Pulse OK Bus Zone Over Current Trip Directional Earth Fault Trip Earth Fault Trip Transformer Differential Trip Bus Zone Trip Frame Leakage Trip Directional Over Current Trip Over Current Trip Table 4 - Table 4 Binary Indications Analogue Indication The following analogue indications shall be provided to SCADA: Current (at least 1 phase) for each circuit breaker Bus voltage (at least 1 phase) for each switchboard Current transducers shall be provided to allow monitoring of primary circuit currents by SCADA. They shall be mean-sensing, self-powered AC current transducers. The transducers shall be connected in series with B phase of protection CT circuit or where required by suitable metering CT s. Approved types and details provided in specification EP SP, Protection System Requirements for the High Voltage Network Controls The following control functions from the SCADA system are to be provided for: Circuit Breaker Open (trip) RailCorp Page 22 of 31

23 Circuit Breaker Close Circuit Test Facilities Each circuit-breaker panel shall incorporate an integral type circuit test facility. All test facilities shall be suitable for the application of d.c. test voltages associated with the after-installation testing of power cables, and shall be rated for the same system voltage as the switchgear. The test facility shall facilitate the connection of test equipment with the circuit earthed and then allow the earths to be removed with the test equipment still connected. It shall be possible to connect a hand applied earthing set to the circuit side of each circuit breaker panel for use in conjunction with test equipment. It shall be possible to apply or remove the earth connection independent of the application or removal of the test equipment connection. It is permissible that external removable accessories be used to achieve this function. 8 Integrated System Support Requirements 8.1 Integrated Support Objectives The switchgear manufacturer must establish and provide the information required to operate and maintain the equipment throughout its operational life, in a cost effective manner and to a level that is consistent with the planned operational performance and usage of the switchgear. This includes: Specifying Maintenance Requirements. Spares Support. Operations and Maintenance Manuals. Training, and Support Equipment and Tooling. 8.2 Equipment Supplier Deliverable The Integrated support requirements are a significant deliverable in the procurement of new Switchgear. Manuals, training, documentation and other support deliverable's shall be in accordance with EP SP - Electrical Power Equipment - Integrated Support Requirements. RailCorp Page 23 of 31

24 9 Tests Testing requirements are to be read in conjunction with the specification EP SP, Common Requirements for Electric Power Equipment. 9.1 Routine Tests Routine tests as listed in: AS 2650, Section 7 IEC , Section 7 IEC , Section 7 shall be carried out on each panel. 9.2 Type Tests The results of type tests as required in: AS 2650 IEC IEC shall be made available by the supplier upon request. Test certificate details, demonstrating compliance with the above standards, including the date, results and name of the testing body shall be supplied in Appendix A. Type test certificates for each of these tests will be accepted where it can be demonstrated that the switchgear supplied is of a similar design to previously type tested switchgear. 10 Data Set associated with the Equipment The following data shall be supplied by the manufacturer and maintained for the switchgear. This data will remain the property of RailCorp Information The information requirements set out in the following standards apply: EP SP EP SP EP SP EP SP Electrical Power Equipment - Integrated Support Requirements Common Requirements for Electric Power Equipment. Controls & Protection for Rectification Equipment Protection System Requirements for the High Voltage Network 10.2 Technical Schedule (Appendix A) The information listed in the technical schedule of Appendix A, supplied by the manufacturer, shall be maintained for each switchboard Life Cycle Costing All the data and assumptions pertaining to the determination of the whole-of-life cost calculations shall be recorded. RailCorp Page 24 of 31

25 Appendix A Technical Schedule The manufacturer shall supply the information listed in this technical schedule. Switchgear information: manufacturer country of origin catalogue/type designation total switchgear mass, kg Circuit breaker type (SF6 / Vacuum) Switchboard General arrangement drawing showing overall dimensions (h, w, d in mm), cable termination locations and required space around unit for access and arc venting requirements for Single circuit-breaker panel 3 circuit breaker unit switchboard with bus VT and arc duct (if applicable) 4 circuit breaker unit switchboard with bus VT and arc duct (if applicable) 5 circuit breaker unit switchboard with bus VT and arc duct (if applicable) Required clearances at sides, rear & top of switchboard. Required clearance at front of switchboard for installation and removal Cable trench width Switchgear Ratings: Voltage, Busbar Normal Current Insulation Level,: Peak lightning impulse withstand voltage, Short duration power frequency withstand voltage, Short time withstand current (I k ), Peak withstand current (I p ), Duration of short time current (tk), Short circuit breaking current, Short circuit making current, Ambient conditions assumed for stated current ratings above Current ratings of switchgear at worst case ambient conditions given in RailCorp specification: EP SP, Electrical Power Equipment - Design Ranges of Ambient Condition kv A kv kv kv ka ka S ka ka RailCorp Page 25 of 31

26 Switchgear IEC Classifications: Internal arc classification Internal arc test current, Internal arc test duration Circuit breaker mechanical durability class Circuit breaker electrical durability class Switch disconnector mechanical durability class Switch disconnector electrical durability class Earth switch mechanical durability class Earth switch electrical durability class Details of lifting and slinging for individual panels and 3,4 & 5 unit switchboards Surge arrestor types accommodated Surge arrester mounting details / restrictions Description of panel busbar interconnection arrangements Description of all operational and safety interlocking arrangements Table of all possible and inhibited states that the circuit-breakers and switches in the switchgear may occupy. Analysis demonstrating the integrity of all interlocking arrangements which includes an analysis of all possible failure modes and the controls designed in to manage them Auxiliary supply voltage Is the switchgear self powered? Clearance hole or stud size of earthing bar offered Gas used for insulation In which compartments is the gas used? Detail of gas pressure monitoring device. Quantity of the SF6 to be used in each separately filled compartment? Specify the degree of SF6 gas tightness for the switchgear. If the circuit-breaker is a vacuum type state the method of indicating vacuum loss (if any) Does the circuit-breaker panel include in-line off-load disconnectors? Is the switch disconnector offered 2-way or 3-way? Details of the circuit earthing facilities offered including the method of indicating the position of the earthing switch and guaranteeing the integrity of that indication ka Yes/No 2 or 3 RailCorp Page 26 of 31

27 Diameter of the earthing clamping screw Supply voltage, peak power and steady power of the springs charge motor (where applicable) Type of circuit-breaker closing mechanism offered Rating of each circuit-breaker closing device Voltage and peak power ratings for the continuous operation of the circuit-breaker coils Is a solenoid circuit-breaker operating mechanism an option and if so what is its power rating Number of circuit breaker spare auxiliary contacts Type of circuit test facility offered Description of test plugs to be used Type of switch-disconnector offered Type of test facility offered Maximum size and number of HV cables that can be terminated in each circuit-breaker panel. Clearly specify clearances between each cable termination of each phase. Provision of a detailed dimensioned drawing of the arrangement is required. Type of cable termination offered. Specify manufacturer, model and full details of separable insulated connector. Detail shielding arrangement to be included. Peak and stand-by power requirements of the switchgear, Type and ratings of live line indicators CT and VT space limitations and mounting arrangements (for CTs provide details for both bus and circuit sides of the circuit breaker). Can the busbar VTs be accommodated in circuit-breaker panels? If busbar VTs cannot be mounted in the circuit breaker panel then describe the mounting arrangement and dimensions Number and details of the current transformers offered for each function: type encapsulation material class burden tap ratios tap points knee-point voltage secondary resistance excitation current at knee-point voltage VA RailCorp Page 27 of 31